实验三Linux_C_程序设计

1、?Linux程序开发环境?实验报告实验成绩：批阅教师：年 月 日实验3 Linux C程序设计1、实验目的（1） 掌握Linux shell程序运行方法 （2） 掌握Linux Shell程序根本语法（3） 了解Linux环境变量（4） 编写简单Linux shell程序 2、实验内容使用curses库完成CD唱片管理系统的C语言简单用户界面版。实验步骤见附录。3、实验记录（1） 实验报告中提交系统的完整脚本；#include <unistd.h>#include <stdlib.h>#include <stdio.h>#include <string

2、.h>#include <curses.h>#define MAX_STRING (80)/* Longest allowed response */#define MAX_ENTRY (1024)/* Longest allowed database entry */#define MESSAGE_LINE 6/* Misc. messages go here */#define ERROR_LINE 22/* The line to use for errors */#define Q_LINE 20/* Line for Questions */#define PROM

3、PT_LINE 18/* Line for prompting on */static char current_cdMAX_STRING = "0"static char current_catMAX_STRING;const char *title_file = "title.cdb"const char *tracks_file = "tracks.cdb"const char *temp_file = "cdb.tmp"/* Prototypes for local functions */void cle

4、ar_all_screen(void);void get_return(void);int get_confirm(void);int getchoice(char *greet, char *choices);void draw_menu(char *options, int highlight, int start_row, int start_col);void insert_title(char *cdtitle);void get_string(char *string);void add_record(void);void count_cds(void);void find_cd(

5、void);void list_tracks(void);void remove_tracks(void);void remove_cd(void);void update_cd(void);/* 菜单项 */char *main_menu = "aadd new CD", "ffind CD", "ccount CDs and tracks in the catalog", "qquit", 0,;/* The extended menu is displayed when a CD is currently s

6、elected */char *extended_menu = "aadd new CD", "ffind CD", "ccount CDs and tracks in the catalog", "llist tracks on current CD", "rremove current CD", "uupdate track information", "qquit", 0,;int main() int choice; initscr(); do c

7、hoice = getchoice("Options:", current_cd0 ? extended_menu : main_menu);switch (choice) case 'q': break;case 'a': add_record(); break;case 'c': count_cds(); break;case 'f': find_cd(); break;case 'l': list_tracks(); break;case 'r': remove_cd();

8、 break;case 'u': update_cd(); break; while (choice != 'q'); endwin(); exit(EXIT_SUCCESS);/* main */add menu/* getchoice - ask the user to choose passed: greet, an introduction choices, an array of strings, NULL at end */int getchoice(char *greet, char *choices) static int selected_ro

9、w = 0; int max_row = 0; int start_screenrow = MESSAGE_LINE, start_screencol = 10; char *option; int selected; int key = 0; option = choices; while (*option) max_row+;option+; /* protect against menu getting shorted when CD deleted */ if (selected_row >= max_row)selected_row = 0; clear_all_screen(

10、); mvprintw(start_screenrow - 2, start_screencol, greet); keypad(stdscr, TRUE); cbreak(); noecho(); key = 0; while (key != 'q' && key != KEY_ENTER && key != 'n') if (key = KEY_UP) if (selected_row = 0)selected_row = max_row - 1; elseselected_row-;if (key = KEY_DOWN) i

11、f (selected_row = (max_row - 1)selected_row = 0; elseselected_row+;selected = *choicesselected_row;draw_menu(choices, selected_row, start_screenrow, start_screencol);key = getch(); keypad(stdscr, FALSE); nocbreak(); echo(); if (key = 'q')selected = 'q'return (selected);void draw_menu

12、(char *options, int current_highlight, int start_row, int start_col) int current_row = 0; char *option_ptr; char *txt_ptr; option_ptr = options; while (*option_ptr) if (current_row = current_highlight) attron(A_STANDOUT);txt_ptr = optionscurrent_row;txt_ptr+;mvprintw(start_row + current_row, start_c

13、ol, "%s", txt_ptr);if (current_row = current_highlight) attroff(A_STANDOUT);current_row+;option_ptr+; mvprintw(start_row + current_row + 3, start_col, "Move highlight then press Return "); refresh();/* clear_all_screen Clear the screen and re-write the title. If a CD is selected

14、then display the information. */void clear_all_screen() clear(); mvprintw(2, Q_LINE, "%s", "CD Database Application"); if (current_cd0) mvprintw(ERROR_LINE, 0, "Current CD: %s: %sn", current_cat, current_cd); refresh();/* get_return Prompt for and read a carriage return

15、. Ignore other characters. */void get_return() int ch; mvprintw(23, 0, "%s", " Press return "); refresh(); while (ch = getchar() != 'n' && ch != EOF);/* get_confirm Prompt for and read confirmation. Read a string and check first character for Y or y. On error or o

16、ther character return no confirmation. */int get_confirm() int confirmed = 0; char first_char = 'N' mvprintw(Q_LINE, 5, "Are you sure? "); clrtoeol(); refresh(); cbreak(); first_char = getch(); if (first_char = 'Y' | first_char = 'y') confirmed = 1; nocbreak(); if (

17、!confirmed) mvprintw(Q_LINE, 1, " Cancelled");clrtoeol();refresh();sleep(1); return confirmed;/database operation/* Database File Manipulation Functions */* insert_title Add a title to the CD database Simply add the title string to the end of the titles file */void insert_title(char *cdtit

18、le) FILE *fp = fopen(title_file, "a"); if (!fp) mvprintw(ERROR_LINE, 0, "cannot open CD titles database"); else fprintf(fp, "%sn", cdtitle);fclose(fp); /* get_string At the current screen position prompt for and read a string Delete any trailing newline. */void get_stri

19、ng(char *string) int len; wgetnstr(stdscr, string, MAX_STRING); len = strlen(string); if (len > 0 && stringlen - 1 = 'n')stringlen - 1 = '0'/* add_record Add a new CD to the collection */void add_record() char catalog_numberMAX_STRING; char cd_titleMAX_STRING; char cd_type

20、MAX_STRING; char cd_artistMAX_STRING; char cd_entryMAX_STRING; int screenrow = MESSAGE_LINE; int screencol = 10; clear_all_screen(); mvprintw(screenrow, screencol, "Enter new CD details"); screenrow += 2; mvprintw(screenrow, screencol, "Catalog Number: "); get_string(catalog_numb

21、er); screenrow+; mvprintw(screenrow, screencol, " CD Title: "); get_string(cd_title); screenrow+; mvprintw(screenrow, screencol, " CD Type: "); get_string(cd_type); screenrow+; mvprintw(screenrow, screencol, " Artist: "); get_string(cd_artist); screenrow+; mvprintw(15,

22、5, "About to add this new entry:"); sprintf(cd_entry, "%s,%s,%s,%s", catalog_number, cd_title, cd_type, cd_artist); mvprintw(17, 5, "%s", cd_entry); refresh(); move(PROMPT_LINE, 0); if (get_confirm() insert_title(cd_entry);strcpy(current_cd, cd_title);strcpy(current_cat

23、, catalog_number); /* count_cds - scan the database and count titles and tracks */void count_cds() FILE *titles_fp, *tracks_fp; char entryMAX_ENTRY; int titles = 0; int tracks = 0; titles_fp = fopen(title_file, "r"); if (titles_fp) while (fgets(entry, MAX_ENTRY, titles_fp) titles+;fclose(t

24、itles_fp); tracks_fp = fopen(tracks_file, "r"); if (tracks_fp) while (fgets(entry, MAX_ENTRY, tracks_fp) tracks+;fclose(tracks_fp); mvprintw(ERROR_LINE, 0, "Database contains %d titles, with a total of %d tracks.", titles, tracks); get_return();/* find_cd - locate a CD in the dat

25、abase prompt for a substring to match in the database set current_cd to the CD title */void find_cd() char matchMAX_STRING, entryMAX_ENTRY; FILE *titles_fp; int count = 0; char *found, *title, *catalog; mvprintw(Q_LINE, 0, "Enter a string to search for in CD titles: "); get_string(match);

26、titles_fp = fopen(title_file, "r"); if (titles_fp) while (fgets(entry, MAX_ENTRY, titles_fp) /* Skip past catalog number */ catalog = entry; if (found = strstr(catalog, ",") *found = 0;title = found + 1;/* Zap the next comma in the entry to reduce it to title only */if (found = s

27、trstr(title, ",") *found = '0' /* Now see if the match substring is present */ if (found = strstr(title, match) count+;strcpy(current_cd, title);strcpy(current_cat, catalog); fclose(titles_fp); if (count != 1) if (count = 0) mvprintw(ERROR_LINE, 0, "Sorry, no matching CD found

28、. ");if (count > 1) mvprintw(ERROR_LINE, 0, "Sorry, match is ambiguous: %d CDs found. ", count);current_cd0 = '0'get_return(); /* remove_tracks - delete tracks from the current CD */void remove_tracks() FILE *tracks_fp, *temp_fp; char entryMAX_ENTRY + 1; int cat_length; if

29、(current_cd0 = '0')return; cat_length = strlen(current_cat); tracks_fp = fopen(tracks_file, "r"); if (tracks_fp = (FILE *)NULL) return; temp_fp = fopen(temp_file, "w"); while (fgets(entry, MAX_ENTRY, tracks_fp) /* Compare catalog number and copy entry if no match */if (st

30、rncmp(current_cat, entry, cat_length) != 0) fputs(entry, temp_fp); fclose(tracks_fp); fclose(temp_fp); unlink(tracks_file); rename(temp_file, tracks_file);/* remove_cd - delete the current CD from the database */void remove_cd() FILE *titles_fp, *temp_fp; char entryMAX_ENTRY; int cat_length; if (cur

31、rent_cd0 = '0')return; clear_all_screen(); mvprintw(PROMPT_LINE, 0, "About to remove CD %s: %s. ", current_cat, current_cd); if (!get_confirm()return; cat_length = strlen(current_cat); /* Copy the titles file to a temporary, ignoring this CD */ titles_fp = fopen(title_file, "r

32、"); temp_fp = fopen(temp_file, "w"); while (fgets(entry, MAX_ENTRY, titles_fp) /* Compare catalog number and copy entry if no match */if (strncmp(current_cat, entry, cat_length) != 0) fputs(entry, temp_fp); fclose(titles_fp); fclose(temp_fp); /* Delete the titles file, and rename the

33、temporary file */ unlink(title_file); rename(temp_file, title_file); /* Now do the same for the tracks file */ remove_tracks(); /* Reset current CD to 'None' */ current_cd0 = '0'/* Some defines we use only for showing or entering the track information */#define BOXED_LINES 11#define

34、BOXED_ROWS 60#define BOX_LINE_POS 8#define BOX_ROW_POS 2/* list_tracks - list the tracks for the current CD */void list_tracks() FILE *tracks_fp; char entryMAX_ENTRY; int cat_length; int lines_op = 0; WINDOW *track_pad_ptr; int tracks = 0; int key; int first_line = 0; if (current_cd0 = '0')

35、mvprintw(ERROR_LINE, 0, "You must select a CD first. ", stdout);get_return();return; clear_all_screen(); cat_length = strlen(current_cat); /* First count the number of tracks for the current CD */ tracks_fp = fopen(tracks_file, "r"); if (!tracks_fp)return; while (fgets(entry, MAX

36、_ENTRY, tracks_fp) if (strncmp(current_cat, entry, cat_length) = 0) tracks+; fclose(tracks_fp); /* Make a new pad, ensure that even if there is only a single track the PAD is large enough so the later prefresh() is always valid. */ track_pad_ptr = newpad(tracks + 1 + BOXED_LINES, BOXED_ROWS + 1); if

37、 (!track_pad_ptr)return; tracks_fp = fopen(tracks_file, "r"); if (!tracks_fp)return; mvprintw(4, 0, "CD Track Listingn"); /* write the track information into the pad */ while (fgets(entry, MAX_ENTRY, tracks_fp) /* Compare catalog number and output rest of entry */if (strncmp(curr

38、ent_cat, entry, cat_length) = 0) mvwprintw(track_pad_ptr, lines_op+, 0, "%s", entry + cat_length + 1); fclose(tracks_fp); if (lines_op > BOXED_LINES) mvprintw(MESSAGE_LINE, 0, "Cursor keys to scroll, RETURN or q to exit"); else mvprintw(MESSAGE_LINE, 0, "RETURN or q to ex

39、it"); wrefresh(stdscr); keypad(stdscr, TRUE); cbreak(); noecho(); key = 0;while (key != 'q' && key != KEY_ENTER && key != 'n') if (key = KEY_UP) if (first_line > 0)first_line-;if (key = KEY_DOWN) if (first_line + BOXED_LINES + 1 < tracks)first_line+;/* now

40、draw the appropriate part of the pad on the screen */prefresh(track_pad_ptr, first_line, 0, BOX_LINE_POS, BOX_ROW_POS, BOX_LINE_POS + BOXED_LINES, BOX_ROW_POS + BOXED_ROWS);/*wrefresh(stdscr); */key = getch(); delwin(track_pad_ptr); keypad(stdscr, FALSE); nocbreak(); echo();/* update_cd - re-enter t

41、racks for current CD deletes all tracks for the current CD in the database and then prompts for new ones. */void update_cd() FILE *tracks_fp; char track_nameMAX_STRING; int len; int track = 1; int screen_line = 1; WINDOW *box_window_ptr; WINDOW *sub_window_ptr; clear_all_screen(); mvprintw(PROMPT_LI

42、NE, 0, "Re-entering tracks for CD. "); if (!get_confirm()return; move(PROMPT_LINE, 0); clrtoeol(); remove_tracks(); mvprintw(MESSAGE_LINE, 0, "Enter a blank line to finish"); tracks_fp = fopen(tracks_file, "a"); /* Just to show how, enter the information in a scrolling,

43、 boxed, window. The trick is to set-up a sub-window, draw a box around the edge, then add a new, scrolling, sub-window just inside the boxed sub-window. */ box_window_ptr = subwin(stdscr, BOXED_LINES + 2, BOXED_ROWS + 2, BOX_LINE_POS - 1, BOX_ROW_POS - 1); if (!box_window_ptr)return; box(box_window_

44、ptr, ACS_VLINE, ACS_HLINE); sub_window_ptr = subwin(stdscr, BOXED_LINES, BOXED_ROWS, BOX_LINE_POS, BOX_ROW_POS); if (!sub_window_ptr)return; scrollok(sub_window_ptr, TRUE); werase(sub_window_ptr); touchwin(stdscr); do mvwprintw(sub_window_ptr, screen_line+, BOX_ROW_POS + 2, "Track %d: ", track);clrtoeol();refresh();wgetnstr(sub_window_ptr, track_name, MAX_STRING);len = strlen(track_name);if (len